The courtship song of fanning males in the fruit fly parasitoid Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)

In this paper we acoustically describe the wing fanning behaviour showed by the male of the braconid Psyttalia concolor toward females and other conspecific males. P. concolor is a synovigenic koinobiont larval-pupal endoparasitoid of many Tephritidae, used in olive crops to control the Olive Fruit Fly Bactrocera oleae (Rossi). In this braconid male wing fanning produces a courtship song characterized by sequences of homogenous pulses with harmonic structure and fundamental frequency of about 180 Hz. Song parameters can vary according to the behavioural context. Statistically significant differences, both in terms of pulse frequency and duration, characterize fanning towards females in comparison with male-male approaches. Moreover, the pulse duration is associated to the fanning song displayed before a successful courtship. Our observations allowed to define the air-borne component of the sound and to definitely confirm the exclusive role of the wings in signal production in sexual communication of P. concolor.